Island



(No Model.) 3 Shasta-Sheet 1.

R. NEWTON. MECHANICAL STOKBR FURNACE.

No. 513,244. Patented Jan. 23, 1894.

' -(No Model.) 3 Sheets-Sheet 2.

R. NEWTON. MECHANICAL STOKER FURNACE.

No. 513,244. Patented Jan. 23, 1894.

(No Model.) a sheets-sheet 3.

R. -NEWTON. MECHANICAL STOKER FURNACE.

No. 513,244. v Patented Jan. 23, 1894.

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NITED STATE PATENT OFFICE.

ROBERT NEl/VTON, OF PROVIDENCE, RHODE ISLAND.

TMECHANICAL-STOKER FURNACE.

SPECIFICATION forming part of Letters Patent No. 513,244, dated January23, 1894. Applicationfiled March 19,1891. Serial No. 385.579. (N0model.)

To aZZ whom it may concern.-

Be it known that 1, ROBERT NEWTON, of the city of Providence, in thecounty of Providence and State of Rhode Island, have invented a new anduseful Improvement in MechanicaLStoker Furnaces; and I hereby declarethat the following is a full, clear, and exact description of the same,reference being had to the accompanying drawings, forming part of thisspecification.

This invention has reference to furnaces in which the fuel is suppliedby mechanical devices.

The invention is applicable to steam-generators and all other furnacesin which coal is burned.

In mechanical stokers, as heretofore-constructed, the grates, on whichthe fuel is supported, are liable to warp and parts of the grates areliable to be melted and burned owing to the high temperature in thefurnace and the exposed position of these parts. In such mechanicalstokers the fuel is supplied to the furnace from an opening of lesstransverse width than the transverse width of the furnace and istherefore not evenly distributed over the surface of the grate; thesides of the grate being supplied with less fuel than the center, thedraft of air through the sides of the grates is therefore greater thanin the center.

In furnaces provided with mechanical stokers the fuel is supplied at thefront end of the grate and is carried forward gradually to thebridge-wall end of the grate where the residue of the burned, orpartially burned, fuel is delivered into a receptacle from which it isfrom time to time discharged; the heat at this bridge-wall end of thefurnace is so great that the metal of the ends of the grates will burnor melt unless it is protected against this excessive heat.

The object of this invention is to so construct the furnace that theexposed parts of the grates shall be protected against injury, the fueldelivered evenly over the whole width of the grate, the interior of thefurnace be readily accessible, the supply of fuel easily regulated aswell as the forward movement of the fuel on the grate; and to these endsmy invention consists in the peculiar and novel construction of thevarious parts,

as will-be more fully set forth hereinafter and pointed out in theclaims.

Figure 1 is a vertical sectional view of a furnace provided withmyimproved mechanical stoker in which the ends of the grate-bars areprotected by ashes. Fig. 2 is a side view of a furnace showing themechanism for operating the mechanical stoker. Fig. 3 is a frontelevation of a furnace provided with my improved mechanical stoker.

Corresponding numerals indicate corresponding parts in the drawings.

The numerals 2 indicate walls on each side of the furnace; 3 the ironfrontof the furnace. This front is shown as extending only across theupper part of the opening between the two side-walls 2. The lower partis usually closed and provided with a door through which the ash-pit canbe reached.

at is the hopper through which the fuel is supplied to the fuel-chamber5, the plate 6 forming the bottom of the fuel-chamber.

7 is the dead-plate forming the inclined bottom of the stoke-hole 8.

The vertically-sliding gate 9 is provided near each end with atoothed-rack 10 and is operated by the pinions 11 secured to atransverse horizontal shaft and engaging with the rack 10. The shaft isprovided at one end with the crank 12 by turning which the gate 9 may beraised or lowered and the opening from the fuel-chamber to thestoke-hole adjusted so as to regulate the thickness of the bed of fueldelivered to the furnace.

The front of the fuel-chamber 5 is formed by the slab 13 the ends ofwhich enter vertical-grooves formed on the inner sides of the end orcheek pieces 14. The lower edge of the.

slab 13 is concaved and rests on the upper rounded edge of thepush-plate 15; this plate is firmly secured to the horizontal shaft 16which shaft extends through the vertical slot in the end or check pieces14:. The spiralsprings 17, placed between a bolster resting on the shaft16 and a bridge-piece 18 secured to the cheek-piece and extending acrossthe slot, exert pressure on the shaft 16 sufficient to hold the loweredge of the push-plate 15 in contact with the plate 6 and yet, yield tothe required rising of the shaft 16, as the pushplate 15 oscillates withthe shaft to push the fuel into the furnace.

To the shaft 16 the slotted arm 19 is firmly secured and in the slot thewrist-pin 20 is ad- Justably secured. The lever 21 is passed over thewrist-pin 20 and is secured by the pin 22 extending diagonally under thewrist pin. The pin 22 can be readily withdrawn and the lever 21 can thenbe raised off from the wristpin 20. The opposite end of the arm 21 isconnected by the stud-pin 23 with the worm-gear 25, the stud-pin 23being provided with a threaded shank extending through the radialslot24in the worm-gear 25 and is secured therein adjustably by a nut, as isshown in Fig. 3. The worm-gear 25 is secured to one end of thehorizontal shaft 26, which shaft is journaled in suitable bearings, andon the opposite end of the shaft 26 the disk 27 is secured, so as torotate with the shaft. The stud-pin 28 is adjustably secured to the disk27, a radial slot being formed in the disk to permit the adjustment ofthe stud-pin 28 nearer to or farther from the center of the disk 27. Thelink 29 connects the stud-pin 28 with the lever 30, the end of whichlever being provided with a number of holes by any one of which the link29 may be connected with the lever 30. The lever 30 is connected to therocker 31 which extends transversely under the grate, the ends beingjournaled in the side-frames 32 The grate is form ed of the stationarygratebars 32 and the reciprocating grate-bars 33 placed between thefixed grate bars or tubes,

, and these reciprocating grate-bars 33 are provided with a notch intowhich the upper part of the rocker 31 enters, so that when the rocker isoscillated on its end-bearings the grate-bars 33 will be moved forwardand backward and will be slightly raised and lowered during thesemovements. The upper edges of the gratebars are formed intosaw-toothshaped projecting angles having one short vertical and onelonger approximately horizontal side. Motion is imparted to thismechanism by means of the worm-shaft supported in suitable bearings andengaging with the worm-gear 25. The worm-shaft 34 isprovided with one ormore pulleys 35 connected by the belt 36 with an over-headdriving-shaft. The

driving-shaft is not shown. It may be arranged in the usual manner, orit may be a counter-shaft driven from the main-shaft.

The operation of this mechanism, when properly adjusted, controls thesupply of the fuel and the combustion of the same in the furnace. Themotion transmitted'by the belt 36 to the worm-shaft 34 turns theworm-gear 25 and with the same the disk 27. The rotary motion of theworm-gear 25 is changed into the reciprocating motion of the lever 21and, as this lever is connected with the slottedarm 19 by the stud-pin20, the reciprocating motion of the lever 21 is transmitted and changedinto the oscillating motionof the arm 19 and the pusher-plate 15. Thefuel delivered through the funnel 4 to the fuel-chamber 5 is pushed, bythe forward motion of the lower part of the pusher plate 15, through theopening controlled by the gate 9 into the stokehole and over theinclineddead-plate7 onto the grate. By the adjustment of the stud-pins 23 and20, either or both,the extent of,or sweep of, theoscillating'pusher-plate 15 can be regulated and thereby the fuel pushedinto the furnace regulated, while the gate 9 regulates the thickness ofthe bed of coal. The weight of the slab 13, which rests on thepusher-plate 15, and also the pressure of the springs 17 hold the loweredge of the pusher-plate 15 in close contact with the bed-plate 6 andalso permit the shaft 16 to rise as the pusher-plate approaches theperpendicular position. During the outward swing of the pusher-plate 15the fuel descends by gravity, so that the fuelchamber 5 is at all timesfilled with fuel and it requires to be so filled at all times, at leastto the upper edge of the pusher-plate, to insure the delivery of therequired quantity. The fuel so delivered on the grate is pushed forwardby the reciprocating motion and the rising of the reciprocating grates33 to which motion is transmitted, from the Worm-gear 25, the shaft 26,and disk 27, by the link 29 connecting the disk with the lever 30, whichimparts oscillating motion to the rocker 31. The extent of thisreciprocation of the gratebars 33 can be regulated by the adjustment ofthe wrist-pin 28 and the connection of the link 29 with the lever 30.

While the stoker and the mechanism for operating the same are applicableto any kind, or form, of furnace and may be used in connection with anykind of grate on which the fuel is carried forward mechanically, or bygravity, the construction of the furnace proper is a most essential andimportant feature in a mechanical stoker in which the reciprocatinggrate-bars must be protected so as to retain their freedom to move thefuel forward from the dead-plate toward ,the bridge and thus maintainthe continuity of the bed of fuel, and the burned, or partially burned,

fuel must be delivered into a receptacle between the end of the grateand the bridgewall 51 which is usually provided with a dumping-grate.

In Fig. 1 the supporting plate 41 is provided with the inclined side 44wide enough to form the required pocket, and the hinged dumping-grate 45is made solidat its forward end and is held against the bearing 41 bythe toggle-jointed levers 46 drawn forward by the rod 47 provided withthe hook 48 for securing'the rod to the front 3 and at its end with thehandle 49. By this construction the air is prevented from entering thefuel at the closed portion of the dumping-grate and the burned, orpartially burned, fuel and ashes protect this portion of the furnace andthe ends of the grate-bars, while the refuse can be readily dumped intothe ash-pit.

Having thus described my invention, I claim as new and desire to secureby Letters Patent--- 1. In a mechanical stoker, in combination,

a grate adapted to move the fuel forward from the dead-plate, afuel-chamber, or reservoir, having a fixed bottom or bed-plate,apusherplate, pivoted at its upper end in vertically yielding bearings,adapted to push the fuel out of the fuel-chamber, and a gate, providedat each end with a rack and pinion, adapted to regulate the thickness ofthe bed of fuel, as described.

2. The combination in a mechanically controlled furnace with the fixedand the reciprocating grate-bars, of the bearing-plate 41 provided withthe inclined side 44, the dumping-grate 45 the forward portion of whichis imperforate, the toggle-jointed levers 46, and the rod 47, as and forthe purpose herein set forth.

3. In a mechanically fed and operated furnace, the combination with thehopper 4, the fuel-chamber 5, the stoke-hole 8, the deadplate 7, thebed-plate 6 forming the bottom of the fuel-chamber, the push-platehinged at its upper end the lower end sweeping over the surface of thebed-plate, the arm 19 adapted to vibrate the push-plate to feed the fuelto the furnace, the reciprocating grate-bars 33, the rocker 31, and themechanism, substantially as described, for operating the arm 19 androcker 31, as and for the purpose described.

4. The combination with a grate adapted to move the fuel forward, thestoke-hole, and the dead-plate, of a fuel-chamber placed in front of thestoke-hole having a fixed bed-plate forming the bottom of thefuel-chamber, the pivoted push-plate 15 journaled in the vertical slotsin the ends of the fuel-chamber, the

slab 13 and the springs 17 adapted to hold the lower edge of thepush-plate in contact with the bed-plate, the arm 19, and mechanism foroperating the push-plate to feed the fuelinto the furnace, as described.

5. In a mechanical stoker, the combination 6. The combination with thedead-plate 7,,

the vertically adjustable gate 9, the fuel-chamber 5 having the fixedbed-plate 6 forming the bottom of the fuel-chamber, the hinged pushplate15, the shaft 16, the arm 19 secured to the shaft, the reciprocatinggrate-bars 33, and the pivoted-rocker 31, of the worm-shaft 34 adaptedto be driven from a prime motor, the worm-gear provided with anadjustable wrist-pin, the lever 21 connecting the wormgear with the arm19, the shaft 26, the disk 27 secured to the shaft and provided with thewrist-pin, thelink 29, and lever 30, the whole adapted to feed the fuelto the furnace and move the same forward on the grate, as described.

ROBERT NEWTON.

Witnesses:

JOSEPH A. MILLER, Jr., HENRY J. MILLER.

